Resource partitioning for sidelink

Abstract

Wireless communications systems and methods related to resource partitioning for sidelink are provided. A first user equipment (UE) transmits a time division duplex (TDD) configuration to a second UE, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link. The first UE receives, from the second UE, a first communication signal over the first link in a resource of the first set of resources. The first UE transmits, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of and priority to U.S. Patent Application No. 17 / 489,419, filed September 29, 2021, and U.S. Provisional Patent Application No. 63 / 198,212, filed October 2, 2020, the entire contents of which are incorporated by reference. TECHNICAL FIELD

[0003] The present disclosure is directed to wireless communication systems and methods. Certain embodiments enable and provide techniques for sidelink resource allocation and partitioning. BACKGROUND

[0004] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system can include a number of base stations (BSs), each simultaneously supporting communications for multiple communication devices, which can be otherwise known as user equipment (UE).

[0005] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system can include a number of base stations (BSs), each simultaneously supporting communications for multiple communication devices, which can be otherwise known as user equipment (UE).

[0006] In wireless communication networks, a BS can communicate with UEs in the uplink and downlink directions. Sidelink was introduced in LTE to allow a UE to transmit data to another UE without tunneling through a BS and / or associated core network. LTE sidelink technology has been extended to provide device-to-device (D2D) communications, vehicle-to- everything (V2X) communications, and / or cellular vehicle-to-everything (C-V2X) communications. Similarly, NR can be extended to support sidelink communications, D2D communications, V2X communications, and / or C-V2X over licensed and / or unlicensed bands. SUMMARY

[0007] The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the present disclosure, and is not intended to identify key or critical elements of the present disclosure or to delineate the scope of any or all aspects thereof. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in a general

[0008] For example, in one aspect of the disclosure, a method of wireless communication performed by a first user equipment (UE) includes receiving, from a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; receiving, from the second UE, a first communication signal over the first link in a resource of the first set of resources; and transmitting, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

[0009] In an additional aspect of the disclosure, a method of wireless communication performed by a first user equipment (UE) includes transmitting, to a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; transmitting, to the second UE, a first communication signal over the first link using a resource of the first set of resources; and receiving, from the second UE, a second communication signal over the second link in a resource of the second set of resources.

[0010] In an additional aspect of the disclosure, a first user equipment (UE) includes a transceiver configured to receive, from a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; receive, from the second UE, a first communication signal over the first link in a resource of the first set of resources; and transmit, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

[0011] In an additional aspect of the disclosure, a first user equipment (UE) includes a transceiver configured to: transmit, to a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; transmit, to the second UE, a first communication signal over the first link using resources in the first set of resources; and receive, from the second UE, a second communication signal over the second link in resources in the second set of resources.

[0012] In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon, the program code comprising: code for causing a first user equipment (UE) to receive, from a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; code for causing the first UE to receive, from the second UE, a first communication signal over the first link in resources in the first set of resources; and code for causing the first UE to transmit, to the second UE, a second communication signal over the second link using resources in the second set of resources.

[0013] In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon, the program code comprising: code for causing a first user equipment (UE) to transmit, to a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; code for causing the first UE to transmit, to the second UE, a first communication signal over the first link using resources in the first set of resources; and code for causing the first UE to receive, from the second UE, a second communication signal over the second link in resources in the second set of resources.

[0014] In an additional aspect of the disclosure, a first user equipment (UE) includes means for receiving, from a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; means for receiving, from the second UE, a first communication signal over the first link in a resource of the first set of resources; and means for transmitting, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

[0015] In an additional aspect of the disclosure, a first user equipment (UE) includes means for transmitting, to a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; means for transmitting, to the second UE, a first communication signal over the first link using a resource of the first set of resources; and means for receiving, from the second UE, a second communication signal over the second link in a resource of the second set of resources.

[0016] Other aspects, features, and embodiments of the application will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments of the application in conjunction with the accompanying figures. While features of the present application can be discussed relative to certain embodiments and figures below, all embodiments of the application can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments can be discussed as having certain advantageous features, one or more of such features can also be used in accordance with the various embodiments of the application discussed herein. In similar fashion, the exemplary embodiments described herein can be directed to a device, system, or method, and can include one or more of the advantageous features discussed herein. In other words, while the exemplary embodiments can be discussed as devices, systems, or methods, the exemplary embodiments can also be used in devices, systems, or methods. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A wireless communication network is shown in accordance with some aspects of the disclosure.

[0018] Figure 2 A wireless communication network is shown in accordance with some aspects of the disclosure.

[0019] Figure 3 A sidelink communication scheme is shown in accordance with some aspects of the disclosure.

[0020] Figure 4A sidelink deployment scenario is shown in accordance with some aspects of the disclosure.

[0021] Figure 5 A sidelink deployment scenario is shown in accordance with some aspects of the disclosure.

[0022] Figure 6 A sidelink communication scheme showing resource pool partitioning in accordance with some aspects of the disclosure.

[0023] Figure 7 A sequence diagram showing sidelink forward / reverse link resource partitioning in accordance with some aspects of the disclosure.

[0024] Figure 8 A block diagram of an exemplary user equipment (UE) in accordance with some aspects of the disclosure.

[0025] Figure 9 A block diagram of an exemplary base station (BS) in accordance with some aspects of the disclosure.

[0026] Figure 10 A flow diagram of a communication method in accordance with some aspects of the disclosure.

[0027] Figure 11 A flow diagram of a communication method in accordance with some aspects of the disclosure. DETAILED DESCRIPTION

[0028] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0029] The present disclosure relates generally to wireless communication systems (also referred to as wireless communication networks). In various embodiments, techniques and apparatus can be used for wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, LTE networks, Global System for Mobile Communications (GSM) networks, 5thGeneration (5G) or new radio (NR) networks, as well as other communications networks. As used herein, the terms“network” and“system” can be used interchangeably.

[0030] An OFDMA network can implement a radio technology such as evolved UTRA (E- UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDMA, etc. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS). In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) and CDMA2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project that aims to improve the UMTS mobile phone standard. The 3 GPP can define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution of wireless technology from LTE, 4G, 5G, NR, and beyond, sharing access to wireless spectrum across these networks using some new and different radio access technology or radio air interface.

[0031] In particular, 5G networks contemplate diverse deployment scenarios and diverse spectrum usage, including: licensed, license-exempt, and shared spectrum. For example, 5G networks can be implemented in frequency bands at 3.5 GHz, 4.9 GHz, 27 GHz, 70 GHz, etc. In order to implement these goals, further enhancements to LTE and LTE-A are considered in addition to the development of new radio technology for 5G NR networks. 5G NR will be capable of scaling to deliver not only the ultra-mobility and ultra-low latency of 5G, but also the ultra-coverage of 5G. 2 2

[0032] ​​A 5G NR communications system can be implemented to use an optimized OFDM- based waveform with scalable numerology and transmission time intervals (TTIs). Additional features can also include a common, flexible framework to efficiently multiplex services and features with dynamic, low-latency time division duplex (TDD) / frequency division duplex (FDD) design, and advanced wireless technologies such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR (with scaling of subcarrier spacing) can efficiently address the operation of diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of sub-3 GHz FDD / TDD implementations, subcarrier spacing can occur at 15 kHz, for example, over 5, 10, 20 MHz, and so on bandwidths (BW). For other various outdoor and small cell coverage TDD deployments greater than 3 GHz, subcarrier spacing can occur at 30 kHz over 80 / 100 MHz BW. For other various indoor wideband implementations using TDD over the unlicensed portion of the 5 GHz band, subcarrier spacing can occur at 60 kHz over 160 MHz BW. Finally, for various deployments transmitting with mmWave components at 28 GHz in TDD, subcarrier spacing can occur at 120 kHz over 500 MHz BW.

[0033] The scalable numerology of 5G NR facilitates scalable TTIs for various latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmissions to start at symbol boundaries. 5G NR also envisions a self-contained, integrated subframe design with UL / downlink scheduling information, data, and acknowledgements in the same subframe. The self-contained, integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL / downlink, which can be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet current traffic demands.

[0034] Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein can be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein can be implemented independently of any other aspects and that two or more aspects can be combined in various ways. For example, an apparatus can be implemented or a method can be practiced using any number of the aspects set forth herein. In addition, such an apparatus can be implemented or such a method can be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method can be implemented as part of a system, device, apparatus, and / or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect can comprise at least one of the enumerated elements.

[0035] Sidelink communication refers to communication between user equipment devices (UEs) without tunneling through a base station (BS) and / or core network. Sidelink communication can be transmitted through a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH). The PSCCH and PSSCH are analogous to a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) in downlink (DL) communication between a BS and a UE. For example, the PSCCH can carry sidelink control information (SCI) and the PSSCH can carry sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, where the SCI in the PSCCH can carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. In some implementations, the SCI in the PSCCH can be referred to as SCI part 1 (SCI-1) and additional SCI (which can be referred to as SCI part 2 (SCI-2)) can be carried in the PSSCH. The SCI-2 can include control information (e.g., transmission parameters, modulation coding scheme (MCS)) that is more specific to the data carriers in the PSSCH. Use cases for sidelink communication can include V2X, enhanced mobile broadband (eMBB), industrial IoT (IIoT), NR-lite, and / or NR-super-lite. NR-lite can refer to a scaled down version of NR in terms of UE power consumption, capability, and / or cost. NR-super-lite can refer to a further scaled down version of NR in terms of UE power consumption, capability, and / or cost.

[0036] As used herein, the term “sidelink UE” can refer to a user equipment that performs device-to-device communication or other types of communication with another user equipment independently of any tunneling through a BS (e.g., gNB) and / or associated core network. As used herein, the term “sidelink transmitter UE” can refer to a user equipment that performs sidelink transmission operations. As used herein, the term “sidelink receiver UE” can refer to a user equipment that performs sidelink reception operations. As used herein, the terms “synchronization UE,” “sidelink synchronization UE,” “anchor UE,” or “sidelink anchor UE” refer to a sidelink UE that transmits S-SSBs to facilitate sidelink communications among multiple sidelink UEs (e.g., when operating in a standalone sidelink system), and these terms are interchangeable without departing from the scope of the present disclosure. As used herein, the terms “relay UE” or “sidelink relay” refer to a UE that is within the coverage of a BS that acts as a relay node between the BS and another UE. As used herein, the term “remote UE” refers to a UE that communicates with a BS via a relay UE. A sidelink UE can act as a transmitter sidelink UE at one time and as a receiver sidelink UE at another time. A sidelink synchronization UE, relay UE, or remote UE can also act as a transmitter sidelink UE at one time and as a receiver sidelink UE at another time.

[0037] For sidelink over licensed spectrum, NR supports two radio resource allocation modes (RRAs), Mode 1 RRA and Mode 2 RRA. Mode 1 RRA supports network-controlled RRA, which can be used for in-coverage sidelink communications. For example, a serving BS (e.g., gNB) can determine radio resources on behalf of a sidelink UE and transmit an indication of the radio resources to the sidelink UE. In some aspects, the serving BS utilizes downlink control information (DCI) to grant a sidelink transmission. However, for this mode, there is a large amount of base station involvement and is only operable when the sidelink UE is within the coverage area of the serving BS. Mode 2 RRA supports autonomous RRA, which can be used for out-of-coverage sidelink UEs or partial-coverage sidelink UEs. For example, a serving BS can configure a sidelink resource pool to a sidelink UE (e.g., when it is within coverage of the serving BS), which can be used for sidelink when the sidelink UE is out of coverage of the serving BS. The serving BS can also configure the sidelink UE to act as a sidelink anchor UE to provide sidelink system information for out-of-coverage sidelink UEs to communicate sidelink communications. For example, a sidelink anchor UE can provide sidelink system information by broadcasting a sidelink synchronization signal block (S-SSB). The S-SSB can be similar to an SSB broadcast by a BS. For example, the S-SSB can include a synchronization signal and / or sidelink system information. Some examples of sidelink system information can include a sidelink bandwidth part (BWP) configuration, one or more sidelink transmit resource pools and / or one or more sidelink receive resource pools, S-SSB transmission related parameters (e.g., a sidelink slot configured for S-SSB transmission and / or a S-SSB transmission periodicity), and / or any other configuration information related to sidelink communications. In some implementations, an anchor UE can also schedule other sidelink UEs for communications. Thus, a sidelink anchor UE can act as a small gNB to facilitate and / or coordinate communications between sidelink UEs. A sidelink channel over which two UEs can directly communicate with each other can also be referred to as a PC5 interface.

[0038] Advances in wireless communication technology (e.g., NR) have primarily focused on providing high-end services (e.g., eMBB) to high-end smartphones that can have high processing and / or power capabilities, and / or services for vertical industries (e.g., URLLC and V2X). To address scalability, NR-lite is introduced to enable more efficient, more economical deployments, for example, by relaxing (reducing) peak data throughput, latency, and / or reliability. Thus, NR-lite can be more suitable for serving mid-end UEs that have lower capabilities than high-end UEs. As use cases and different deployment scenarios continue to expand in wireless communications, further complexity and / or power reduction can enable support for low-power wide-area (LPWA) deployments. For example, NR-super-lite with further reduced capabilities can support low-end UEs that have lower capabilities than mid-end UEs. Some example use cases for NR-super-lite can include service interactions related to smart metering, asset tracking, and / or personal IoT applications (e.g., health monitoring). Thus, there is a need to improve coverage, complexity, and / or power consumption.

[0039] In some aspects, networks can utilize sidelink to improve coverage, power consumption, and / or complexity for low-end UEs. For example, in some use cases, sidelink transmissions can support UE-to-network relaying, where an in-coverage UE is able to relay signals between a gNB and an out-of-coverage UE (remote UE). Using a relay UE to relay communications between a gNB and a remote UE can improve power efficiency by avoiding a large number of radio signal repetitions (e.g., up to 2048 repetitions) that can otherwise be required to extend coverage. In some instances, a remote UE can measure a received signal indicator (RSSI) level from a gNB, and if the RSSI is below a predefined threshold, the remote UE can connect to an in-coverage relay UE. Subsequently, the in-coverage relay UE can receive data and control signaling from the gNB, boost the signal power, and transmit them to the sidelink remote UE. In some instances, the remote out-of-coverage UE can be in the same cell as the sidelink relay UE. In some other instances, the remote UE can be in a different cell than the sidelink relay UE.

[0040] In some use cases, sidelink transmissions can be utilized to support short-range communications, such as wearable or in-home new wearable communications. For example, in short-range sidelink communications, a sidelink UE (relay) can be utilized to support relaying of signals from a gNB to several low-power wearable devices. Further, in some use cases, sidelink relays can be utilized to support low-power modes of operation in certain technologies, such as vehicle-to-everything (V2X) systems. V2X systems enable vehicles to communicate with surrounding traffic and the environment using short-range communications. In V2X systems, sidelink relays can be utilized to reduce power consumption of the communicating devices connected to the sidelink relay.

[0041] In some aspects, a sidelink UE can support half-duplex communications. In other words, a sidelink UE can either transmit or receive at any given time, but cannot perform both transmission and reception simultaneously. Thus, the total amount of resources in a pool of sidelink resources is shared between transmission and reception. One issue with half-duplex communications is that when a sidelink UE is transmitting in a sidelink resource, the sidelink UE can not be able to monitor other sidelink resources simultaneously. As such, if another sidelink UE transmits SCI indicating a reservation of future sidelink resources in one of the other resources, the UE can not detect the SCI and thus can not be aware of the reservation. If the UE determines to transmit in the reserved sidelink resources, the UE can cause a collision or interference and impact sidelink performance.

[0042] This application describes mechanisms for resource partitioning between a forward link and a reverse link for sidelink communications to support half-duplex transmissions. The forward link can refer to a sidelink in a transmission direction from a relay UE to a remote UE. The reverse link can refer to a sidelink in a transmission direction from a remote UE to a relay UE. For example, a relay UE can partition resources in a sidelink resource pool into a first set of resources for communications on the forward link and a second set of resources for communications on the reverse link. The first set of resources is non-overlapping with the second set of resources to provide half-duplex communications between the relay UE and the remote UE. The first set of resources can include PSCCH resources and PSSCH resources. Similarly, the second set of resources can include PSCCH resources and PSSCH resources. The relay UE can transmit a time division duplex (TDD) configuration to the remote UE. The TDD configuration can indicate the first set of resources associated with the forward link and the second set of resources associated with the reverse link. Thus, the remote UE can receive the TDD configuration indicating the first set of resources for the forward link and the second set of resources for the reverse link. In some aspects, the relay UE can transmit data and control signaling to the remote UE over the forward link using resources from the first set of resources. Thus, the remote UE can receive data and control signaling from the relay UE over the forward link in resources from the first set of resources. In some aspects, the remote UE can transmit data and control signaling to the relay UE over the reverse link using resources from the second set of resources. Thus, the relay UE can receive data and control signaling from the remote UE over the reverse link in resources from the second set of resources. In some aspects, the first set of resources and the second set of resources are time division multiplexed with DL / UL transmissions in a frame, and the relay UE can receive an allocation of the sidelink resource pool from a base station (BS).

[0043] In some aspects, the relay UE can perform a semi-static resource partitioning, and thus the TDD configuration can be a semi-static configuration. For example, the partitioning of the resource pool into the first set of resources for the forward link and the second set of resources for the reverse link can be the same for a relatively long period of time (e.g., tens of seconds, tens of minutes, hours). In some aspects, the relay UE can transmit a sidelink broadcast message including the TDD configuration indicating the resource partitioning information, e.g., via a physical sidelink broadcast channel (PSBCH). In some other aspects, the relay UE can transmit a sidelink discovery message including the TDD configuration indicating the resource partitioning information during a sidelink discovery procedure in which the relay UE and the remote UE can discover each other.

[0044] In some other aspects, the relay UE can perform dynamic resource partitioning, and thus the TDD configuration can be a dynamic configuration. The relay UE can transmit, e.g., via PSCCH or PSSCH, sidelink channel information (SCI) including a TDD configuration indicating resource partitioning information. In some aspects, the TDD configuration includes a slot format indicator indicating a slot format for an upcoming slot. For example, a new SCI format (e.g., SCI3) can be defined to provide forward / backward sidelink resource partitioning information. In some aspects, the relay UE can transmit a slot format indicator indicating resource partitioning information. For example, the relay UE can periodically transmit the slot format indicator to indicate forward / backward link resources in a sidelink resource pool for a certain duration (e.g., about 1 ms, 2 ms, or tens of milliseconds). Thus, the remote UE can receive the slot format indicator and update resource partitioning according to the slot format indicator.

[0045] Aspects of the disclosure can provide several benefits. For example, when the relay UE is an advanced UE (e.g., a high-end or mid-end UE) and the remote UE is an NR ultra-light UE, resource partitioning between forward and reverse links can provide power-efficient sidelink operation, as the remote UE can communicate with a nearby relay UE rather than a distant BS. Moreover, the sidelink resource partitioning proposed in the disclosure can provide a low-power operation mode for V2X systems. Furthermore, performing resource partitioning between forward and reverse links can address the half-duplex data transmission problem (where a UE can transmit or receive at a given time) and thus improve sidelink data rate and power efficiency.

[0046] Figure 1 A wireless communication network 100 according to some aspects of the disclosure is shown. The network 100 can be a 5G network. The network 100 includes multiple base stations (BSs) 105 (labeled as 105a, 105b, 105c, 105d, 105e, and 105f, respectively) and other network entities. A BS 105 can be a station that communicates with UEs 115 and can also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS 105 can provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS 105 and / or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0047] The BSs 105 can provide communication coverage for a macro cell or a small cell such as a pico cell or femto cell, and / or other types of cells. A macro cell can generally cover a relatively large geographic area (e.g., several kilometers in radius) and can allow unrestricted access by UEs with service subscriptions with the network provider. A small cell such as a pico cell can also cover a relatively small geographic area and can allow restricted access by UEs such as UEs in the same home as a subscriber of the network provider or UEs for which a pico cell operator has purchased service provider subscriptions. A small cell such as a femto cell can also cover a relatively small geographic area and can be used to provide restricted access by UEs such as UEs in the same home as a subscriber of the network provider. A BS for a macro cell can be referred to as a macro BS. A BS for a small cell can be referred to as a small cell BS, a pico BS, a femto BS, or a home BS. In Figure 1 In the example shown in FIG. 1, the BSs 105d and 105e can be regular macro BSs, while the BSs 105a-105c can be macro BSs implementing one of three-dimensional (3D) MIMO, full-dimension (FD) MIMO, or massive MIMO. The BSs 105a-105c can utilize their higher dimension MIMO capabilities to increase coverage and capacity with 3D beamforming in both elevation and azimuth beams. The BS 105f can be a small cell BS, which can be a home node or a portable access point. A BS can support one or multiple (e.g., two, three, four, etc.) cells.

[0048] The network 100 can support synchronous or asynchronous operation. For synchronous operation, the BSs can have similar frame timing, and transmissions from different BSs can be approximately aligned in time. For asynchronous operation, the BSs can have different frame timing, and transmissions from different BSs can not be aligned in time.

[0049] The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 can be stationary or mobile. A UE 115 can also be referred to as a terminal, a mobile station, a subscriber unit, a station, etc. A UE 115 can be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, etc. In one aspect, a UE 115 can be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE can be a device that does not include a UICC. In some aspects, UEs 115 that do not include UICCs can also be referred to as IoT devices or Internet of Everything (IoE) devices. UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100 A UE 115 can also be a machine specifically configured to Figure 1 In general, a lightning bolt (e.g., communication link) indicates a wireless transmission between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and / or uplink (UL), an intended transmission between BSs 105, a backhaul transmission between BSs, or a sidelink transmission between UEs 115.

[0050] In operation, BSs 105a- 105c can serve UEs 115a and 115b using 3D beamforming and coordinated spatial techniques such as coordinated multipoint (CoMP) or multi-connectivity. Macro BS 105d can perform backhaul communications with BSs 105a- 105c, as well as small cell BS 105f. Macro BS 105d can also transmit a multicast service reserved for and received by UEs 115c and 115d. Such a multicast service can include mobile television or stream video, or can include other services for providing community information, such as weather emergencies or alerts (e.g., amber alerts or gray alerts).

[0051] The BSs 105 can also communicate with a core network. The core network can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which can be an example of a gNB or an access node controller (ANC)) can interface with the core network (e.g., through an NG2, NG3, etc. interface) and can perform radio

[0052] The network 100 can also utilize ultra-reliable and redundant communication links to support mission critical communications for mission critical devices, such as the UE 115e, which can be an example of an unmanned aerial vehicle. Redundant communication links with the UE 115e can include links from the macro BS 105d and the BS 105e, as well as a link from the small cell BS 105f. Other machine type devices, such as the UE 115f (an example of a thermometer), the UE 115g (an example of a smart power meter), and UE 115h (an example of a wearable device) can communicate through the network 100 with the BS, such as the small cell BS 105f, or the macro BS 105e, either directly

[0053] In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system can partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier can be modulated with data. In some instances, the subcarrier spacing of adjacent subcarriers can be fixed, and the total number of subcarriers (K) can be dependent on the system BW. The system BW can also be partitioned into subbands. In other instances, the spacing of the subcarriers, and / or the duration of TTIs, can be scalable.

[0054] In some aspects, the BS 105 can allocate or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RBs)) for downlink (DL) and uplink (UL) transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame can be divided into multiple subframes or slots (e.g., about 10). Each slot can be further divided into mini-slots. In FDD mode, simultaneous UL and DL transmissions can occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame can be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame can be used for UL transmissions.

[0055] A DL subframe and a UL subframe can be further divided into several regions. For example, each DL or UL subframe can have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BS 105 and the UE 115. For example, the reference signals can have a particular pilot pattern or structure, where pilot tones can span across the operating BW or frequency band, all located at a pre-defined time and a pre-defined frequency. For example, the BS 105 can transmit cell-specific reference signals (CRS) and / or channel state information - reference signals (CSI-RS) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 can transmit sounding reference signals (SRS) to enable a BS 105 to estimate a UL channel. Control information can include resource assignments and protocol

[0056] In some aspects, the network 100 can be an NR network deployed over a licensed spectrum. The BSs 105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in the network 100 to facilitate synchronization. The BSs 105 can broadcast system information associated with the network 100 (e.g., including a master information block (MIB), remaining system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some instances, the BSs 105 can broadcast the PSS, the SSS, and / or the MIB in the form of synchronization signal blocks (SSBs) over a physical broadcast channel (PBCH) and can broadcast the RMSI and / or the OSI over a physical downlink shared channel (PDSCH).

[0057] In some aspects, a UE 115 attempting to access the network 100 can perform an initial cell search by detecting a PSS from a BS 105. The PSS can enable synchronization of periodic timing and can indicate a physical layer identification value. The UE 115 can then receive an SSS. The SSS can enable radio frame synchronization and can provide a cell identification value that can be combined with the physical layer identification value to identify the cell. The PSS and the SSS can be located in the center portion of a carrier, or can be anywhere in the carrier as appropriate.

[0058] After receiving the PSS and the SSS, the UE 115 can receive a MIB. The MIB can include system information for initial network access and scheduling information for RMSI and / or OSI. After decoding the MIB, the UE 115 can receive the RMSI and / or the OSI. The RMSI and / or the OSI can include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource sets (CORESETs) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

[0059] After obtaining the MIB, the RMSI, and / or the OSI, the UE 115 can perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure can be a four-step random access procedure. For example, the UE 115 can transmit a random access preamble and the BS 105 can respond with a random access response. The random access response (RAR) can include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, a UL grant, a temporary cell radio network temporary identifier (C-RNTI), and / or a backoff indicator. Upon receiving the random access response, the UE 115 can transmit a connection request to the BS 105 and the BS 105 can respond with a connection response. The connection response can indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some examples, the random access procedure can be a two-step random access procedure in which the UE 115 can transmit a random access preamble and a connection request in a single transmission and the BS 105 can respond by transmitting a random access response and a connection response in a single transmission.

[0060] After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, in which operational data can be exchanged. For example, the BS 105 can schedule the UE 115 for UL and / or DL communication. The BS 105 can transmit a UL and / or DL scheduling grant to the UE 115 via a PDCCH. The scheduling grant can be transmitted in the form of a DL control information (DCI). The BS 105 can transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH in accordance with the DL scheduling grant. The UE 115 can transmit a UL communication signal to the BS 105 via a PUSCH and / or a PUCCH in accordance with the UL scheduling grant.

[0061] In some aspects, the network 100 can operate over a system BW or a component carrier (CC) BW. The network 100 can partition the system BW into multiple BWPs (e.g., portions). The BS 105 can dynamically allocate a BWP (e.g., a portion of the system BW) for the UE 115 to operate on. The allocated BWP can be referred to as the active BWP. The UE 115 can monitor the active BWP for signaling information from the BS 105. The BS 105 can schedule the UE 115 for UL or DL communication in the active BWP. In some aspects, the BS 105 can allocate a pair of BWPs within a CC to the UE 115 for UL and DL communication. For example, the BWP pair can include one BWP for UL communication and one BWP for DL communication.

[0062] In some aspects, the network 100 can operate over a shared channel, which can include a shared frequency band or an unlicensed frequency band. For example, the network 100 can be an NR-unlicensed (NR-U) network operating over an unlicensed frequency band. In such aspects, the BSs 105 and UEs 115 can be operated by multiple network operating entities. To avoid collisions, the BSs 105 and UEs 115 can employ LBT procedures to monitor for transmission opportunities (TXOPs) in the shared channel. A wireless communication device can perform LBT in the shared channel. LBT is a channel access scheme that can be used in unlicensed spectrum. When the outcome of LBT is LBT pass (the wireless communication device wins contention for the wireless medium), the wireless communication device can access the shared medium to transmit and / or receive data. For example, a transmitting node (e.g., a BS 105 or a UE 115) can perform LBT before transmitting in the channel. When LBT passes, the transmitting node can proceed with the transmission. When LBT fails, the transmitting node can refrain from transmitting in the channel. In an example, LBT can be based on energy detection. For example, when the measured signal energy from the channel is below a threshold, the outcome of LBT is pass. Conversely, when the measured signal energy from the channel exceeds the threshold, the outcome of LBT is fail. In another example, LBT can be based on signal detection. For example, when no channel reservation signal (e.g., a predetermined preamble signal) is detected in the channel, the outcome of LBT is pass. Conversely, when a channel reservation signal is detected in the channel, the outcome of LBT is fail. A TXOP can also be referred to as a channel occupancy time (COT).

[0063] In some aspects, the network 100 can provide sidelink communications to allow a UE 115 to communicate with another UE 115 without needing to Figure 2The BS 105 and / or core network tunneling is shown in the middle. As described above, sidelink communications can be conveyed through PSCCH and PSSCH. For example, the PSCCH can carry SCI and the PSSCH can carry SCI and / or sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, where the SCI in the PSCCH can carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. In some examples, a transmitting sidelink UE 115 can indicate SCI in two stages. In a first stage SCI, the UE 115 can transmit SCI in a PSCCH to carry information for resource allocation and decoding of a second stage SCI. The first stage SCI can include at least one of the following: priority, PSSCH resource allocation, resource reservation period (if enabled), PSSCH DMRS pattern (if more than one pattern is configured), second stage SCI format (e.g., size of the second stage SCI), amount of resources for the second stage SCI, number of PSSCH demodulation reference signal (DMRS) ports, modulation and coding scheme (MCS), and / or the like. In a second stage SCI, the UE 115 can transmit SCI in a PSSCH to carry information for decoding the PSSCH. The second stage SCI can include a bit L1 destination identifier (ID), 8 bits L1 source ID, HARQ process ID, new data indicator (NDI), redundancy version (RV), and / or the like. It should be understood that these are examples only and the first stage SCI and / or the second stage SCI can include or indicate additional information or different information than those examples provided. Sidelink communications can also be conveyed through a physical sidelink feedback control channel (PSFCH) that indicates an acknowledgement (ACK)-negative acknowledgement (NACK) for a previously transmitted PSSCH.

[0064] In some aspects, the BS 105 can configure a UE 115 to function as a sidelink synchronization or anchor UE 115 to provide sidelink system information to other sidelink UEs 115 that can be outside of coverage of the BS 105 for sidelink communications. The sidelink synchronization UE 115 can transmit the sidelink system information in the form of an S-SSB. The S-SSB can include a synchronization signal (e.g., a PSS and / or a SSS) and sidelink system information, such as a sidelink BWP configuration, one or more sidelink transmission resource pools, and / or one or more sidelink reception resource pools, a parameter related to S-SSB transmission (e.g., a sidelink slot configured for S-SSB transmission and / or a S-SSB transmission periodicity), and / or any other configuration information related to sidelink communications. In some aspects, the BS 105 can configure the sidelink synchronization UE 115 to transmit the S-SSB according to a synchronization raster defined for NR-U. In some instances, the S-SSB according to the NR-U synchronization raster can have an offset from a lowest frequency of a corresponding sidelink BWP on which the S-SSB is transmitted. In some other aspects, the BS 105 can transmit the S-SSB according to a synchronization raster defined for sidelink. The sidelink synchronization raster can be defined such that the S-SSB can be aligned with a lowest frequency of a corresponding sidelink BWP on which the S-SSB is transmitted.

[0065] In some aspects, a UE 115 can function as a relay sidelink UE 115 based on a pre-configuration or a configuration received from a BS 105. The relay sidelink UE 115 can communicate with at least one remote UE 115. The relay UE 115 can relay signals between the remote UE 115 and the BS 105. According to aspects of the present disclosure, the relay UE 115 can transmit a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, for example, to improve power efficiency. The BS 105 can provide a total resource pool to the relay sidelink UE 115, where the first set of resources is associated with a forward link and the second set of resources is associated with a reverse link. The relay sidelink UE 115 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to a remote sidelink UE 115. For example, the relay sidelink UE 115 can transmit data on a PSSCH and control signaling on a PSCCH in resources from the first set of resources. Further, the relay sidelink UE 115 can receive sidelink data and control signaling (e.g., scheduling information, SCI) from a remote sidelink relay UE 115. For example, the relay UE 115 can receive sidelink data on a PSSCH and control signaling on a PSCCH in resources from the second set of resources.

[0066] According to aspects of the present disclosure, a remote sidelink UE 115 can receive a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, e.g., for improved power efficiency. The first set of resources is associated with a forward link and the second set of resources is associated with a reverse link. The remote sidelink UE 115 can receive sidelink data and control signaling (e.g., scheduling information, SCI) from a relay sidelink UE 110. For example, the remote sidelink UE 115 can receive sidelink data on a PSSCH and receive control signaling on a PCSCH in resources from the first set of resources. Further, the remote sidelink UE 115 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to the remote sidelink relay UE 115. For example, the remote UE 115 can transmit sidelink data on a PSSCH and can transmit control signaling on a PCSCH in resources from the second set of resources.

[0067] According to aspects of the present disclosure, a relay sidelink UE 115 can semi-statically update a remote sidelink UE 115. For example, the relay sidelink UE 115 can transmit a sidelink broadcast message to the remote sidelink UE 115 over a physical sidelink broadcast channel (PSBCH). In this regard, the sidelink broadcast message includes resource partitioning information (e.g., a TDD configuration) indicating a time period (e.g., subframe or slot) allocated in a resource pool for a forward link (from the relay sidelink UE 115 to the remote UE 115) and a time period allocated in the resource pool for a reverse link (from the remote UE 115 to the relay sidelink UE 115). In some other aspects, e.g., during a sidelink discovery procedure, a sidelink relay UE can provide substantially similar resource partitioning information via a discovery message.

[0068] According to aspects of the present disclosure, a relay sidelink UE 115 can dynamically transmit resource partitioning information to a remote sidelink UE 115. In some aspects, the relay sidelink UE 115 can transmit SCI via at least one of a PSCCH or a PSCCH. The SCI can include resource partitioning information between a forward link and a reverse link. In this regard, the remote sidelink UE can receive resource allocations for the forward link and / or the reverse link. In some aspects, the relay sidelink UE 115 can transmit a slot format indicator (SFI) indicating a slot format for a time period within a sidelink resource pool. For example, the slot format can indicate whether a time period in the sidelink resource pool is allocated to the forward link or the reverse link. In some aspects, the relay sidelink UE 115 can transmit the slot format indicator to the remote sidelink UE 115 via a new sidelink channel or a SCI type (e.g., SCI3). In some aspects, the relay sidelink UE 115 can periodically transmit the slot format indicator.

[0069] Figure 2 An example of a wireless communication network 200 providing sidelink communications according to embodiments of the present disclosure is shown. The network 200 can correspond to a portion of the network 100. To simplify the discussion, Figure 2 One BS 205 and five UEs 215 (shown as 215a, 215b, 215c, 215d, and 215e) are shown, but it will be recognized that embodiments of the present disclosure can scale to any suitable number of UEs 215 (e.g., about 2, 3, 4, 6, 7, or more) and / or BSs 205 (e.g., about 2, 3, or more). The BS 205 and UEs 215 can be similar to the BSs 105 and UEs 115, respectively. The BS 205 and UEs 215 can share the same radio frequency band for communications. In some instances, the radio frequency band can be a 2.4 GHz unlicensed band, a 5 GHz unlicensed band, or a 6 GHz unlicensed band. In general, the shared radio frequency band can be at any suitable frequency.

[0070] In the network 200, some of the UEs 215 can communicate with each other in peer-to-peer communications. For example, UE 215c can communicate with UE 215e over a sidelink 254, and can communicate with UE 215d over another sidelink 252. The sidelinks 252 and 254 are unicast, two-way links. Some of the UEs 215 can also communicate with the BS 205 in the UL and / or DL direction via a communication link 253. For example, UEs 215a, 215b are within the coverage area 210 of the BS 205 and can thus communicate with the BS 205. In some instances, UE 215c can act as a relay for UEs 215e, 215d to reach the BS 205. In some aspects, some of the UEs 215 are associated with vehicles (e.g., similar to UEs 115i-k), and the communications over the sidelinks 252 and 254 can be C-V2X communications. C-V2X communications can refer to communications between a vehicle and any other wireless communication device in a cellular network. In some aspects, some of the UEs 215 are IoT devices, such as metering devices, asset tracking devices, health monitoring devices, personal wearable devices, and the communications over the sidelinks 252 and 254 can be IoT data associated with a corresponding service or application.

[0071] In some aspects, UE 215e can act as a sidelink anchor UE, and UE 215c can act as a sidelink receiver UE, where UE 215e transmits system parameter information including timing synchronization signals over a sidelink broadcast channel (e.g., PSBCH) so that UE 215c can receive and recover resource allocation and timing information to facilitate sidelink communications with UE 215e. For ease of explanation and brevity of discussion, the remaining description will be discussed with reference to UE 215c (e.g., a sidelink receiver UE) and UE 215e (e.g., a sidelink anchor UE). Figure 2

[0072] Sidelink discovery of other sidelink transmitter UEs (such as other anchor nodes) can be facilitated by using a transport channel known as a transport sidelink discovery channel (SL-DCH) and its physical counterpart channel (physical sidelink discovery channel (e.g., PSDCH)). In some aspects, a sidelink transmitter UE can transmit one or more announcement messages with zero medium access control overhead generated using a physical layer transport block. For example, UE 215e can broadcast an announcement message over a PSDCH to announce its status as an anchor node.

[0073] ​In various embodiments, a sidelink anchoring UE can utilize a sidelink discovery procedure to perform the following operations: 1) advertise its presence as an anchoring UE to potential proximate sidelink UEs by transmitting a message containing its application information or other useful information fields (e.g., GPS coordinates, time, etc.); and 2) monitor for the presence of other proximate sidelink UEs by detecting and decoding corresponding discovery messages, and respond to a sidelink transmitter UE with a similar discovery message. In some instances, the discovery message can include information regarding the type of discovery being performed and / or the type of content provided by the sidelink transmitter UE (e.g., notification, query). For example, UE 215e can broadcast a discovery message on a PSDCH, where the discovery message includes an indication that the discovery message pertains to an announcement of its anchoring node status.

[0074] In some aspects, UE 215e can perform a sensing operation on one or more of a discovery channel (e.g., PSDCH) or a sidelink broadcast channel (such as PSBCH), depending on the implementation. If UE 215e does not detect an existing anchoring UE on the discovery channel, UE 215e can configure itself as an anchoring UE and broadcast an announcement indicating itself as an anchoring UE. If UE 215e detects an existing anchoring UE, UE 215e can determine whether there is a need for it to become an anchoring node within wireless communications network 200.

[0075] In some aspects, UE 215e can provide a transmission resource pool configuration including configuration information for a discovery resource pool configuration and a control / data communication resource pool configuration. A sidelink receiver UE (e.g., UE 215c) can monitor multiple resources to listen for discovery announcements transmitted by an anchoring UE (e.g., UE 215e) to minimize and / or avoid sidelink UE interference. At the end of the discovery procedure, UE 215e and UE 215c can establish a communication link for sidelink communications.

[0076] Figure 3 A sidelink communication scheme 300 is shown in accordance with some aspects of the disclosure. UEs such as UEs 115 and / or 215 in a network such as network 100 and / or 200 can employ scheme 300. In particular, a sidelink UE can employ scheme 300 for sidelink communications over a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum). The shared radio frequency band can be shared by multiple RATs, as discussed in Figure 2 Figure 3 In scheme 300, the x-axis represents time in some arbitrary unit, and the y-axis represents frequency in some arbitrary unit.

[0077] ​In the scheme 300, a shared radio frequency band 301 is divided into multiple sub-channels or frequency sub-bands 302 (shown as 302 S0 , 302 S1 , 302 S2 , …) in frequency and multiple sidelink frames 304 (shown as 304a, 304b, 304c, 304d, …) in time for sidelink communications. The band 301 can be at any suitable frequency (e.g., around 2.4 GHz, 5 GHz, or 6 GHz). The band 301 can have any suitable BW and can be divided into any suitable number of frequency sub-bands 302. The number of frequency sub-bands 302 can depend on sidelink communication BW requirements. The band 301 can be at any suitable frequency. In some aspects, the band 301 is a 2.4 GHz unlicensed band and can have a bandwidth of around 80 megahertz (MHz) divided into around fifteen 5 MHz frequency sub-bands 302.

[0078] Sidelink UEs (e.g., UEs 115 and / or 215) can be equipped with a wideband receiver and a narrowband transmitter. For example, a UE can utilize a narrowband transmitter to access a frequency sub-band 302 S2 for sidelink transmissions with the frame structure 304. The frame structure 304 is repeated in each frequency sub-band 302. In some instances, as shown in Figure 3 , there can be a frequency gap or guard band between adjacent frequency sub-bands 302, e.g., to mitigate adjacent band interference. Thus, multiple sidelink data can be transmitted simultaneously in different frequency sub-bands 302 (e.g., FDM). The frame structure 304 is also repeated in time. For example, the frequency sub-bands 302 S2 can be segmented in time into multiple frames with the frame structure 304.

[0079] The frame structure 304 includes sidelink resources 306 in each frequency sub-band 302. The legend 305 indicates the type of sidelink channel within the sidelink resources 306. The sidelink resources 306 can have a structure substantially similar to NR sidelink resources. For example, the sidelink resources 306 can include multiple subcarriers or RBs in frequency and multiple symbols in time. In some instances, the sidelink resources 306 can have a duration between around one millisecond (ms) to around 20 ms. Each sidelink resource 306 can include a PSCCH 310 and a PSSCH 320. The PSCCH 310 and the PSSCH 320 can be multiplexed in time and / or frequency. In the illustrated Figure 3In the example of FIG. 3, for each sidelink resource 306, the PSCCH 310 is located during the starting symbol (e.g., about 1 symbol or about 2 symbols) of the sidelink resource 306 and occupies a portion of the corresponding frequency sub-band 302, and the PSSCH 320 occupies the remaining time-frequency resources in the sidelink resource 306. In some instances, the sidelink resource 306 can also include a physical sidelink feedback channel (PSFCH), e.g., located during the ending symbol of the sidelink resource 306. In general, the PSCCH 310, PSSCH 320, and / or PSFCH can be multiplexed within the sidelink resource 306 in any suitable configuration.

[0080] In sidelink communications, to enable a successful decoding of the PSCCH 310 and PSSCH 320 by a sidelink receiver UE, information describing the specific resources and transmission configuration allocated by the sidelink anchor UE for the transmission can be carried in a sidelink control information (SCI). In this regard, control information for sidelink communications can be conveyed in the form of an SCI message. The SCI message can be transmitted over the PSCCH 310 and carries information related to the data transmission over the PSSCH 320.

[0081] The SCI can inform the sidelink receiver UE of the frequency locations of the resource reservation interval, the initial transmission and retransmissions, the time interval between the initial transmission and retransmissions, and the modulation and coding scheme (MCS) used to modulate the data transmitted over the PSSCH 320.

[0082] The SCI message can be populated based on a radio resource allocation mode (e.g., mode 1 RRA or mode 2 RRA). For mode 1 RRA, the SCI can be populated using higher layer information carried by L3 control signaling (e.g., RRC and L1 control signaling configured at a cell (e.g., BS 205)). For mode 2 RRA, the SCI can be populated based on autonomous decisions made by each sidelink anchor UE. The structure of the SCI message can include a frequency hopping flag field, a resource block allocation and hopping resource allocation field, a time resource pattern field, an MCS field, a timing advance field, and a group destination identifier field. The structure of the SCI message can include other additional fields as appropriate to support V2X control signaling. The frequency hopping flag field and the resource block allocation and hopping resource allocation field can provide information for a sidelink receiver UE to identify RBs where a data channel (e.g., PSSCH 320) is located. The sidelink anchor UE can autonomously configure each of these two fields. The identified RBs can belong to a sidelink communication resource pool (e.g., PSSCH resource pool). The time resource pattern field can provide time domain resource allocation for a data channel (e.g., PSSCH 320), and in particular, potential subframes for PSSCH transmission. The MCS field can provide an MCS for PSSCH 320, which can be autonomously selected by the sidelink anchor UE. The timing advance field can provide a sidelink time adjustment for mode 2 RRA or other applicable modes. The group destination identifier field can indicate a group of sidelink receiver UEs that are potentially interested in a transmitted message from the sidelink anchor UE. This can be used by the sidelink receiver UEs to ignore messages destined for other groups of sidelink UEs.

[0083] In some aspects, the SCI message can be processed with transport channel coding to generate an SCI message transport block, followed by physical channel coding to generate a corresponding PSCCH block. The PSCCH block is carried on a corresponding subframe resource unit for transmission. The sidelink receiver UEs can receive one or more resource units on the corresponding subframe to recover the control signaling information, and can extract the data channel allocation and transmission configuration.

[0084] The PSCCH 310 can be used to carry SCI 330. The PSSCH 320 can be used to carry sidelink data. Depending on the sidelink application, the sidelink data can have various forms and types. For example, when the sidelink application is a V2X application, the sidelink data can carry V2X data (e.g., vehicle location information, travel speed and / or direction, vehicle sensor measurements, etc.). Alternatively, when the sidelink application is an IIoT application, the sidelink data can carry IIoT data (e.g., sensor measurements, device measurements, temperature readings, etc.). The PSFCH can be used to carry feedback information, e.g., HARQ ACK / NACK for sidelink data received in an earlier sidelink resource 306.

[0085] In some aspects, the scheme 300 is used to synchronize sidelink communications. In other words, the sidelink UEs are synchronized in time and aligned in terms of symbol boundaries, sidelink resource boundaries (e.g., start time of the sidelink frame 304). For example, the sidelink UEs can perform synchronization in various forms based on sidelink SSBs received from the sidelink UEs and / or NR-U SSBs received from a BS (e.g., BS 105 and / or 205) when within coverage of the BS. In some aspects, the sidelink UEs can be preconfigured with the resource pool 308 in the frequency band 301 when configured within coverage of a serving BS according to a mode 1 RRA. The resource pool 308 can include a plurality of sidelink resources 306.

[0086] In the NR sidelink frame structure, the sidelink frames 304 in the resource pool 308 can be contiguous in time. A sidelink receiver UE (e.g., UE 115 and / or 215) can include a reservation in SCI 330 for a sidelink resource 306 in a later sidelink frame 304. Accordingly, another sidelink UE (e.g., a UE in the same NR-U sidelink system) can perform SCI sensing in the resource pool 308 to determine whether the sidelink resource 306 is available or occupied. For example, if the sidelink UE detects SCI indicating a reservation for the sidelink resource 306, the sidelink UE can refrain from transmitting in the reserved sidelink resource 305. If the sidelink UE determines that there is no detected reservation for the sidelink resource 306, the sidelink UE can transmit in the sidelink resource 306. In this way, SCI sensing can help the UEs identify target frequency sub-bands 302 to reserve for sidelink communications and avoid intra-system collisions with another sidelink UE in the NR-U sidelink system. In some aspects, the UEs can be configured with a sensing window for SCI sensing or monitoring to reduce intra-system collisions.

[0087] In some aspects, a sidelink UE can be configured with a frequency hopping pattern. In this regard, the sidelink UE can hop from one frequency sub-band 302 in one sidelink frame 304 to another frequency sub-band 302 in another sidelink frame 304. In the example shown Figure 3 During the sidelink frame 304a, the sidelink UE transmits SCI 330 in a sidelink resource 306 located in the frequency sub-band 302 S2 During the sidelink frame 304b, the sidelink UE transmits SCI 332 in a sidelink resource 306 located in the frequency sub-band 302 S1 During the sidelink frame 304c, the sidelink UE transmits SCI 334 in a sidelink resource 306 located in the frequency sub-band 302 S1 During the sidelink frame 304d, the sidelink UE transmits SCI 336 in a sidelink resource 306 located in the frequency sub-band 302 S1 During the sidelink frame 304d, the sidelink UE transmits SCI 336 in a sidelink resource 306 located in the frequency sub-band 302 S1 During the sidelink frame 304d, the sidelink UE transmits SCI 336 in a sidelink resource 306 located in the frequency sub-band 302 S0 During the sidelink frame 304d, the sidelink UE transmits SCI 336 in a sidelink resource 306 located in the frequency sub-band 302 S0 During the sidelink frame 304d, the sidelink UE transmits SCI 336 in a sidelink resource 306 located in the frequency sub-band 302

[0088] The SCI can also indicate scheduling information and / or a destination identifier (ID) that identifies a target sidelink receiver UE for the next sidelink resource 306. Thus, a sidelink UE can monitor for SCI transmitted by other sidelink UEs. Upon detecting SCI in a sidelink resource 306, the sidelink UE can determine whether the sidelink UE is the target receiver based on the destination ID. If the sidelink UE is the target receiver, the sidelink UE can proceed to receive and decode the sidelink data indicated by the SCI. In some aspects, multiple sidelink UEs can simultaneously communicate sidelink data in a sidelink frame 304 in different frequency sub-bands (e.g., via FDM). For example, in the sidelink frame 304b, one pair of sidelink UEs can communicate sidelink data using the sidelink resources 306 in the frequency sub-band 302 S2 In the frequency sub-band 302 S1 In the frequency sub-band 302

[0089] Figure 4A sidelink deployment scenario 400 is shown in accordance with some aspects of the present disclosure. The scenario 400 illustrates coverage extension with sidelink. In the scenario 400, relay UEs 415 (shown as 415a, 415b, 415c) are deployed in communication with a BS 405 to extend the coverage 410 of the BS 105. The relay UEs 415a, 415b, 415c can be similar to the UEs 115 and / or the UEs 215. The BS 405 can be similar to the UEs 115 and / or the UEs 215. Although Figure 4 Three relay UEs 415 are shown, but it is to be understood that in other examples, the network can include any suitable number of relay UEs (e.g., on the order of 2, 4, 5, 6, or more). The relay UEs 415 can facilitate communication between the BS 405 and UEs outside of the coverage area 410.

[0090] In the example shown Figure 4 The relay UE 415c acts as a relay for a remote UE 420 outside of the coverage area 410 of the BS 405. The remote UE 420 can be similar to the UEs 115 and / or the UEs 215. In some aspects, the relay UE 415c can be a more advanced UE than the remote UE 420. Although Figure 4 The relay UE 415c is shown acting as a relay for one remote UE 420, but it is to be understood that in other examples, a relay UE can act as a relay for any suitable number of remote UEs (e.g., on the order of 2, 4, 5, 6, or more). The relay UE 415c can receive data and / or control information from the remote UE 420 and forward the received data and / or control to the BS 405. For example, the data and / or control information received from the remote UE 420 is UL data and / or control information intended for the BS 405. The relay UE 415c can also receive data and / or control information from the BS 405 and forward the received data and / or control to the remote UE 420. For example, the data and / or control information received from the BS 405 is DL data and / or control information intended for the remote UE 420. In this way, the relay UE 415c can provide a communication path between the BS 405 and the UE 420 that would otherwise be unreachable by the BS 405. The communication path between the relay UE 415c and the remote UE 420 can be a PC5 interface (shown as sidelink 422). For example, the relay UE 415c and the remote UE 420 can communicate using the sidelink channels PSSCH and / or PSCCH and / or sidelink resources, as discussed above with respect to Figure 3

[0091] ​Utilizing sidelink can extend the coverage area of the BS 405 without increasing system resource utilization. For example, transmissions between the BS 405 and the remote UE 420 can require a large number of repetitions without utilizing the relay UE 415c. For example, the BS 405 can repeat each block of information data in a transmission approximately 2048 times before the remote UE 420 can receive the transmission. Similarly, the remote UE 420 can repeat each block of information data in a transmission approximately 2048 times before the BS 405 can receive the transmission. While using high repetition can potentially allow the BS 405 to communicate with the remote UE 420, using high repetition can increase power consumption at the remote UE 420. For example, when the remote UE 420 is a low-end UE with limited processing and / or power resources, high repetition and / or high power consumption at the remote UE 420 can not be feasible. Thus, the deployment of the relay UE 415c allows the remote UE 420 to communicate with the relay UE 415c, which can be located closer to the remote UE 420 than the BS 405. Thus, the remote UE 420 can communicate with the relay UE 415c without expending a large amount of power. Thus, sidelink can improve the power efficiency of long-range UL and / or DL communications. In some instances, sidelink can extend the range or coverage by providing a power boost of approximately 20 decibels (dB).

[0092] Figure 5 A sidelink deployment scenario 500 is shown in accordance with some aspects of the disclosure. The scenario 500 shows using sidelink for short-range, low-power sidelink communications (e.g., for wearable or home networks). In the scenario 500, a relay UE 515 that is in communication with a BS 505 is deployed to act as a central hub or anchor UE for a remote UE 520. The BS 505 can be similar to the UE 115 and / or the UE 215. The relay UE 515 and / or the remote UE 520 can be similar to the UE 115 and / or the UE 215. However, the relay UE 515 can be a more advanced UE than the remote UE 420. For example, the relay UE 515 can be a high-end UE or a mid-end UE, while the remote UE 420 can be a low-end UE (e.g., a personal wearable device, a health monitoring device, etc.). Although Figure 5 One relay UE 515 is shown serving one remote UE 520, but it should be understood that in other examples, a network can include any suitable number of relay UEs (e.g., approximately 2, 4, 5, 6, or more) serving any suitable number of remote UEs (e.g., approximately 2, 3, 4, 5, or more).

[0093] Similar to scenario 400, relay UE 515 can communicate with remote UE 520 via sidelink 522. However, remote UE 520 can or can not have a communication link established with BS 505, e.g., depending on the type of device in use and / or application. In some other instances, a V2X or D2D system can be deployed in a scenario similar to scenario 500.

[0094] As can be seen from scenarios 400 and 500, sidelinks can be used to improve power efficiency, e.g., for NR-super-lite that focuses on low-end UEs for low power operation.

[0095] Accordingly, the present disclosure provides sidelink resource allocation techniques that can facilitate low power communications over sidelinks, e.g., by partitioning or separating a sidelink resource pool into a first set of resources for communications over a forward link (from a relay UE to a remote UE) and a second set of resources for communications over a reverse link (from a remote UE to a relay UE). The partitioning or separation between forward link resources and reverse link resources can avoid the half-duplex link problem discussed above. In addition, since a remote UE can only need to monitor forward link resources and not reverse link resources, the resource partitioning can reduce the amount of resources in a sidelink resource pool that a remote UE needs to monitor, and thus can provide further power savings at the remote UE.

[0096] Figure 6 A resource partitioning scheme 600 is shown in accordance with some aspects of the present disclosure. Scheme 600 can be employed for sidelink communications in a network, such as that of networks 100 and / or 200, and / or by UEs in scenarios 400 and 500, such as UEs 115, 215, and / or 415, 420, 510, 520. In particular, a sidelink UE can employ scheme 600 to perform resource partitioning, e.g., to allocate time slots to forward and / or reverse links of a sidelink communication. In some aspects, scheme 600 can be employed to partition resources in a sidelink resource pool, e.g., as described above with respect to scenarios 400 and 500. Figure 6In scenario 600, the x-axis represents time in some arbitrary units, and the y-axis represents frequency in some arbitrary units. In scenario 600, a relay UE 615 within a coverage area 610 of a BS 605 and in communication with the BS 605 over a link 606 can act as a relay for a remote UE 620. For example, the relay UE 615 can relay UL communications (received over a reverse link 604) from the remote UE 620 to the BS 605 over the link 606, and / or relay DL communications from the BS 605 over the link 606 to the remote UE 620 over a forward link 602. The BS 605 can be similar to the BSs 105, 205, 405, and / or 505. The relay UE 615 and / or the remote UE 620 can be similar to the UEs 115 and / or 215. In some instances, the relay UE 615 can correspond to the relay UE 415c, and the remote UE 620 can correspond to the UE 420 in scenario 400. In some instances, the relay UE 615 can correspond to the relay 515, and the remote UE 620 can correspond to the remote UE 520 in scenario 500. Scenario 600 can be used in conjunction with scenario 300.

[0097] In scenario 600, the BS 605 can configure resources 630 (e.g., time-frequency resources) for communication with one or more UEs (e.g., UEs 115, 215, 415, 515, and / or 615) in the coverage area 610 of the BS 605. The resources 630 can be on a licensed frequency band or a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum), and can be divided in time as shown. For example, the resources 630 are in units of slots 631, e.g., each slot including approximately 14 symbols. The resources 630 can include UL / DL resources 632 time-multiplexed with sidelink (SL) resources 634 in a time-domain frame. The BS 605 can use the UL / DL resources 632 to communicate with UEs (e.g., the UE 615) within the coverage area 610. In this regard, the UL / DL resources 632 can be further divided into a set of slots 631 for UL communications and another set of slots 631 for DL communications. The SL resources 634 can be used for sidelink communications between the relay UE 615 and the remote UE 620. The BS 605 can configure the relay UE 615 with the resources 630 as shown. The resources 630 can include SL resources only in the time-domain frame, and the BS 605 can use a separate carrier to communicate with UEs (e.g., the UE 615).

[0098] In some respects, the relay UE 615 can determine the sidelink resource pool 640 from the SL resources 634. It should be noted that the sidelink resource pool 640 may include SL resources 634 that are temporally continuous and / or SL resources 634 that are temporally discontinuous. To facilitate half-duplex communication, the relay UE 615 may divide the sidelink resources 634 in the sidelink resource pool 640 into a first set of resources for communication on the forward link 602 (from the relay UE 615 to the remote UE 620) and a second set of resources for communication on the reverse link 604 from the remote UE 620 to the relay UE 615.

[0099] In the example shown Figure 6 In the example, the first resource set 634 (or time slot 631) for the forward link 602 is shown as "F", and the second resource set 634 (or time slot 632) for the reverse link 604 is shown as "R". In other words, the relay UE 615 divides the sidelink resource pool 640 into the SL forward link resource pool 642 and the SL reverse link resource pool 644. In some respects, the SL resource 634 can be similar to Figure 3 Resource 306, each resource includes PSCCH 310 and PSSCH 320. In some instances, slot 631 can be similar to... Figure 3 The side link slot 304. In some other instances, the SL resource pool 640 can span multiple frequency subbands and can have the same... Figure 3 Resource pool 308 has a similar resource pool structure as shown by reference numeral 636 in the accompanying drawings. For example, SL resource pool 640 may include multiple sidelink resources 306 spanning frequency subbands within each time slot, wherein each time slot is allocated to either forward link 602 or reverse link 604.

[0100] To facilitate communication between the relay UE 615 and the remote UE 620, the remote UE 620 can be configured with resource partitioning information. For example, the relay UE 615 can transmit a TDD configuration to the remote UE 620. The TDD configuration can indicate a first set of resources 634 for the forward link 602 and a second set of resources 634 for the reverse link 604. In some aspects, the TDD configuration can provide a resource pattern. For example, the TDD configuration can indicate a pattern of “FFRRFFRRFF...” as shown, to indicate the transmission direction for each resource 634. In general, the partitioning between SL resources for the forward link 602 and the reverse link 604 can be any suitable temporal order, and can be equally or differently partitioned between the forward link 602 and the reverse link 604. In some aspects, the pattern can be for a certain number of slots (e.g., about 10, 20, 30, 40, or more), and can be periodic.

[0101] In some aspects, the relay UE 615 can perform semi-static resource partitioning (for forward link resources and reverse link resources), and can provide information related to the SL resource pool 640 (semi-static TDD configuration) to the remote UE 620 via the PSBCH. For example, the relay UE 615 can be configured to perform similar operations as the synchronization UE as described above, and can transmit a broadcast message indicating the TDD configuration via the PSBCH. In some other aspects, the relay UE 615 and the remote UE 620 can perform sidelink discovery as described above, and the relay UE 610 can provide the TDD configuration or the SL resource pool 640 to the remote UE 620 during the discovery procedure. For example, the relay UE 615 can transmit a discovery message indicating the TDD configuration. In some aspects, the discovery message can be carried in the PSDCH. In some other aspects, the discovery message can be carried in the PSSCH. For example, prior to the resource partitioning configuration, the remote UE 620 can be preconfigured with certain sidelink resources, and can perform sensing in the sidelink resources to monitor for the broadcast message and / or the discovery message indicating the TDD configuration. In some aspects, the semi-static TDD configuration information is provided as RRC signaling.

[0102] After configuring the remote UE 620 with the resource partitioning information, the relay UE 615 can communicate with the remote UE 620 in accordance with the resource partitioning information. In this regard, the relay UE 615 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to the remote UE 620 using resources from the first set of resources (e.g., the SL forward link resource pool 642). For example, the relay UE 615 can transmit data on a PSSCH and control signaling on a PSCCH in resources from the first set of resources. Thus, the remote UE 620 can receive sidelink data on a PSSCH and control signaling on a PSCCH in resources from the first set of resources (e.g., the SL forward link resource pool 642). Further, the remote UE 620 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to the relay UE 615 using resources from the second set of resources (e.g., the SL reverse link resource pool 644). For example, the remote UE 620 can transmit data on a PSSCH and control signaling on a PSCCH in resources from the second set of resources. Thus, the relay UE 620 can receive sidelink data on a PSSCH and control signaling on a PSCCH in resources from the second set of resources (e.g., the SL reverse link resource pool 644).

[0103] In some aspects, the remote UE 620 can receive and decode physical communication channels (e.g., PSCCH 310, PSSCH 320) in the forward resource pool 642 from the relay UE 615 and encode and transmit the PSCCH 310 and PSSCH 320 to the relay UE 615 in the forward resource pool 642. Additionally, the relay UE 615 can receive and decode physical communication channels (e.g., PSCCH 310, PSSCH 320) in the reverse resource pool 644 from the remote UE 620 and encode and transmit the PSCCH 310 and PSSCH 320 to the remote UE 620 in the reverse resource pool 644.

[0104] In some aspects, the relay UE 615 can perform dynamic resource partitioning (for forward link resources and reverse link resources) and can provide information related to the SL resource pool 640 (dynamic TDD configuration) to the remote UE 620 via SCI. In this regard, the relay UE 615 can transmit the SCI to the remote UE 620 in at least one of a PSSCH or a PSCCH channel, where the SCI can include configuration information associated with the sidelink resource pool 640. In some aspects, the relay UE 615 can update the resource partitioning based on traffic demand and / or channel conditions on the forward link 602 and the reverse link 604, and can adapt to changes in the traffic demand and or channel conditions.

[0105] In some aspects, the relay UE 615 can transmit a slot format indicator (SFI) to the remote UE 620 indicating the sidelink resource pool slots (e.g., 642, 644). In some aspects, the SFI can be transmitted over a new sidelink channel (e.g., SCI3). In some aspects, the SFI can indicate a similar slot pattern (e.g., “FFRRFFRRFF”) discussed above with respect to semi-static configuration, but the slot pattern can be for the next set of slots and can not repeat. In some examples, the relay UE 615 can periodically transmit the slot format indicator to the remote UE 620. In some aspects, the remote UE 620 can receive and decode physical communication channels (e.g., PSCCH 310, PSSCH 320) from the relay UE 615 based on the forward resource pool 642 and encode and transmit PSCCH 310 and PSSCH 320 to the relay UE 615 based on the forward source pool 642. Further, the relay UE 615 can receive and decode physical communication channels (e.g., PSCCH 310, PSSCH 320) from the remote UE 620 based on the reverse resource pool 644 and encode and transmit PSCCH 310 and PSSCH 320 to the remote UE 620 based on the reverse resource pool 644.

[0106] Figure 7 is a sequence diagram illustrating a sidelink forward / reverse resource partitioning method 700, in accordance with some aspects of the disclosure. The method 700 can be implemented among the BS 605, the relay UE 615, and the remote UE 620. The method 700 can employ the same or similar techniques as described above with respect to FIG. 6, and can be implemented in a similar manner. Figures 4-6Similar mechanisms discussed above are used for communication. Although the method 700 shows the relay UE 615 communicating with one remote UE 620, it should be understood that in other examples, the relay UE 615 can communicate with any suitable number of remote UEs 620 (e.g., approximately 2, 3, 4, 5, 6, or more) over the sidelink. As illustrated, the method 700 includes a number of enumerated actions, but embodiments of the method 700 can include additional actions before, after, and in between the enumerated actions. In some embodiments, one or more of the enumerated actions can be omitted or performed in a different order.

[0107] At action 705, the BS 605 transmits a resource configuration to the relay UE 615. The resource configuration can indicate a first set of resources for communication over a first link and a second set of resources for communication over a second link. The first set of resources and the second set of resources can be time division multiplexed. The first set of resources can be for communication from the BS 605 to the relay UE 615. The second set of resources can be for communication from the relay UE 615 to the BS 605. In some aspects, the resource configuration can be received via a physical downlink control channel (PDCCH) or a physical broadcast channel (PBCH). In some aspects, the resource configuration can be received via a physical discovery channel (PDISCH). In some aspects, the resource configuration can be received via a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH). Figure 6 The resource allocation can indicate a resource 630 similar to the UL / DL resources and SL resources shown.

[0108] At action 710, the UE relay 615 transmits a time division duplex (TDD) configuration to the remote UE 620, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool. The first set of resources can be for communication over a forward link from the relay UE 615 to the remote UE 620. The second set of resources can be for communication over a reverse sidelink from the remote UE 620 to the relay UE 615. In some aspects, the sidelink resource pool can correspond to the sidelink resource pool 640, and the first set of resources and the second set of resources can correspond to the SL resources labeled with the symbols “F” and “R,” respectively. In some aspects, the relay UE 615 can determine the sidelink resource pool based on a configuration received from the BS 605, and can partition the sidelink resource pool into the first set of resources and the second set of resources. In some other aspects, action 705 can be optional, and the relay UE 615 can determine the sidelink resource pool based on a pre-configuration. In some aspects, the first set of resources can be associated with a first link, and the second set of resources can be associated with a second link. In some aspects, the relay UE 615 can transmit, to the remote UE 620 via a PSBCH, a broadcast message including the TDD configuration. In some aspects, the relay UE 615 can transmit, to the remote UE 620, a physical discovery message including the TDD configuration. In some other aspects, the remote UE 620 can transmit, to the relay UE 615, SCI via at least one of a PSCCH or a PSCCH channel during a sidelink slot. In some aspects, the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources, as discussed above with respect to the TDD configuration 650. Figure 6 In other aspects, the TDD configuration can indicate a periodicity of the TDD resource pattern.

[0109] At act 720, the relay UE 615 can transmit sidelink communication signals to the remote UE 620 using resources in the forward link resource pool, as discussed above in Figure 6 FIG. 6. For example, the relay UE 615 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to the remote UE 620. In some aspects, the relay UE 615 can transmit the sidelink data on a PSSCH and the control signaling on a PSCCH in resources similar to the resources 306 within the first set of resources.

[0110] At act 730, the remote UE 620 can transmit sidelink communication signals to the relay UE 615 using resources in the reverse link resource pool, as discussed above in Figure 6 FIG. 6. For example, the remote UE 620 can transmit sidelink data and control signaling (e.g., scheduling information, SCI) to the relay UE 615. In some aspects, the remote UE 620 can transmit the sidelink data on a PSSCH and the control signaling on a PSCCH in resources similar to the resources 306 within the second set of resources.

[0111] Figure 8 is a block diagram of an example UE 800 according to some aspects of the present disclosure. The UE 800 can be a UE 115 as discussed above with respect to Figure 1 FIG. 1, a UE 215 as discussed above with respect to Figure 2 FIG. 2, a UE 415 or UE 420 as discussed above with respect to Figure 4 FIG. 4, a UE 515 or UE 520 as discussed above with respect to Figure 5 FIG. 5, or a UE 615 or UE 620 as discussed above with respect to Figure 6 FIG. 6. As illustrated, the UE 800 can include a processor 802, a memory 804, a sidelink communication module 808, a transceiver 810 (which includes a modem subsystem 812 and a radio frequency (RF) unit 814), and one or more antennas 816. These elements can be in direct or indirect communication with one another, for example via one or more buses. The sidelink communication module 808 can be implemented as, include, or otherwise leverage one or more components of the processor 802, the modem subsystem 812, the RF unit 814, the memory 804, or any other component(s) of the UE 800.

[0112] The processor 802 can include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device that

[0113] Memory 804 may include cache memory (e.g., cache memory of processor 802), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or combinations of different types of memory. In one aspect, memory 804 includes a non-transitory computer-readable medium. Memory 804 may store instructions 806 or have instructions 806 recorded thereon. Instructions 806 may include instructions that, when executed by processor 802, cause processor 802 to perform various aspects of this disclosure in conjunction with reference to UE 115 (e.g., ...). Figures 2-7 The instructions (806) describe the operations in various aspects. Furthermore, instructions 806 can also be referred to as program code, which can be broadly interpreted as including any type of computer-readable statements.

[0114] The sidelink communication module 808 can be implemented via hardware, software, or a combination thereof. For example, the sidelink communication module 808 can be implemented as a processor, circuitry, and / or instructions 806 stored in memory 804 and executed by processor 802. In some examples, the sidelink communication module 808 can be integrated into the modem subsystem 812. For example, the sidelink communication module 808 can be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 812.

[0115] The sidelink communication module 808 can communicate with various components of the UE 800 to perform various aspects of this disclosure, such as, Figures 2-7 In some respects, UE 800 is similar to... Figure 4 relay UE 415, Figure 5 relay UE515 or Figure 6 The relay side walkway UE of relay UE 615. For example, the side walkway communication module 808 is configured to send a TDD configuration via the side walkway to a second UE (e.g., a remote UE similar to UE 115, 215, 420, 520, or 620), the TDD configuration indicating a first resource set time-division multiplexed with a second resource set in the side walkway resource pool, as described above regarding... Figure 6 The first resource set may be associated with a forward link (e.g., forward link 602), and the second resource set may be associated with a reverse link (e.g., reverse link 604). In some aspects, the first and second resource sets may be similar to... Figure 6The resource pool 640 contains SL resource 634. In some aspects, the sidelink communication module 808 is also configured to: use resources in the first resource set to send a first communication signal to the second UE via a forward link, and receive a second communication signal from the second UE via a reverse link in resources in the second resource set. For example, the sidelink communication 808 may be configured to: encode PSCCH 310 and PSSCH 320 and send them to the second UE using resources from the first resource set, and receive and decode PSCCH 310 and PSSCH 320 from the second UE in resources from the second resource set (e.g., by performing SCI sensing or monitoring in the second resource set).

[0116] In some respects, the sidelink communication module 808 is configured to semi-statically indicate the partitioning between the first resource set and the second resource set. For example, the sidelink communication module 808 may be configured to send a sidelink broadcast message including TDD configuration to the second UE via the PSBCH through the sidelink. In some other instances, the sidelink communication module 808 may be configured to send a sidelink discovery message including TDD configuration (via PSDCH or PSSCH) to the second UE via the sidelink.

[0117] In some aspects, the sidelink communication module 808 is also configured to dynamically indicate the partitioning between the first resource set and the second resource set. For example, the sidelink communication module 808 may also be configured to transmit TDD configuration to the second UE via at least one of PSCCH or PSSCH through the sidelink. The sidelink communication module 808 may also be configured to transmit an SCI including the TDD configuration via at least one of PSCCH or PSSCH. In some aspects, the SCI message may indicate the sidelink slot format (e.g., in SCI3). In some aspects, the sidelink communication module 808 may also be configured to periodically transmit SCI.

[0118] In some respects, UE 800 is similar to Figure 4 Remote UE 420 Figure 5 Remote UE 520 or Figure 6 The remote sidelink UE of the remote UE 620. For example, the sidelink communication module 808 is configured to receive TDD configuration from a second UE (e.g., a relay UE similar to UE 115, 215, 415, 515, or 615) via the sidelink. The TDD configuration indicates a first resource set time-division multiplexed with a second resource set in the sidelink resource pool, as described above regarding... Figure 6The first set of resources can be associated with a forward link (e.g., forward link 602) and the second set of resources can be associated with a reverse link (e.g., reverse link 604). In some aspects, the first set of resources and the second set of resources can be similar to SL resources 634 in resource pool 640. Figure 6 In some aspects, the sidelink communication module 808 is further configured to receive, from the second UE, a first communication signal over the forward link using resources in the first set of resources and transmit, to the second UE, a second communication signal over the reverse link in resources in the second set of resources. For example, the sidelink communication 808 can be configured to encode and transmit PSCCH 310 and PSSCH 320 to the second UE using resources from the second set of resources, and receive and decode (e.g., by performing SCI sensing or monitoring in the first set of resources) PSCCH 310 and PSSCH 320 from the second UE in resources from the first set of resources.

[0119] As shown, transceiver 810 can include modem subsystem 812 and RF unit 814. Transceiver 810 can be configured to communicate bi-directionally with other devices, such as the BS 105. Modem subsystem 812 can be configured to modulate and / or encode data from memory 804 and / or sidelink communication module 808 according to a modulation and coding scheme (MCS) (e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). RF unit 814 can be configured to process modulated / encoded data (e.g., sidelink data, SCI, TDD configuration, forward / reverse link resource partitioning information, sidelink resource pool allocation) from modem subsystem 812 (on outbound transmissions) or of transmissions originating from another source such as a UE 115 or BS 105 (on inbound transmissions) for transmission via the antenna 817. RF unit 814 can be further configured to perform analog beamforming in conjunction with the digital beamforming of the modem subsystem 812. Although shown as integrated with transceiver 810, the modem subsystem 812 and RF unit 814 can be separate devices coupled to one another at the UE 115.

[0120] The RF unit 814 can provide the modulated and / or processed data, e.g. data packets (or more generally data messages that can include one or more data packets and other information), to the antennas 816 for transmission to one or more other devices. The antennas 816 can also receive data messages transmitted from other devices. The antennas 816 can provide the received data messages for processing and / or demodulation at the transceiver 810. The transceiver 810 can provide the demodulated and decoded data (e.g., sidelink data, SCI, TDD configuration, forward / reverse link resource partitioning information, sidelink resource pool allocation) to the sidelink communication module 808 for processing. The antennas 816 can include multiple antennas of similar or different design schemes in order to sustain multiple transmission links. The RF unit 814 can configure the antennas 816.

[0121] In one aspect, the UE 800 can include multiple transceivers 810 implementing different RATs (e.g., NR and LTE). In one aspect, the UE 800 can include a single transceiver 810 implementing multiple RATs (e.g., NR and LTE). In one aspect, the transceiver 810 can include various components, where different combinations of components can implement different RATs.

[0122] Figure 9 is a block diagram of an example BS 900 that can be a BS 105 in the network 100 as discussed above in Figure 1 , a BS 205 as discussed above in Figure 2 , a BS 405 as discussed above in Figure 4 , a BS 505 as discussed above in Figure 5 , or a BS 605 as discussed above in Figure 6 . As illustrated, the BS 900 can include a processor 902, a memory 904, a sidelink configuration module 908, a transceiver 910 (which includes a modem subsystem 912 and a RF unit 914), and one or more antennas 916. These elements can be in direct or indirect communication with one another, for example via one or more buses. The BS 900 can be a standalone device or be part of a component of a larger device.

[0123] The processor 902 can have various features as a specific-type processor. These can include, for example, a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 902 can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0124] Memory 904 can include cache memory (e.g., of processor 902), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, memory 904 can comprise a non-transitory computer-readable medium. Memory 904 can store instructions 906. Instructions 906 can include instructions that, when executed by processor 902, enable processor 902 to perform operations described herein (e.g., aspects of Figures 2-7

[0125] Sidelink configuration module 908 can be implemented via hardware, software, or combinations thereof. For example, sidelink configuration module 908 can be implemented as a processor, circuit, and / or instructions 906 stored in memory 904 and executed by processor 902. In some examples, sidelink configuration module 908 can be integrated within modem subsystem 912. For example, sidelink configuration module 908 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within modem subsystem 912.

[0126] Sidelink configuration module 908 can communicate with various components of BS 900 to perform various aspects of the present disclosure, for example, aspects of Figures 2-7 Sidelink configuration module 908 is configured to configure a UE (e.g., UEs 115, 215, 415, and / or 515) with a pool of sidelink resources for sidelink communications. In some aspects, sidelink configuration module 908 can configure a UE with a pool of resources (e.g., resource pool 640), as discussed above with respect to Figure 6 and Figure 7 In some aspects, sidelink configuration module 908 can communicate with a relay UE and a remote UE (via the relay UE), as discussed above with respect to Figures 4-6

[0127] ​​As illustrated, transceiver 910 can include modem subsystem 912 and RF unit 914. Transceiver 910 can be configured to communicate bi-directionally with other devices, for example, UE 115 and / or another core network element. Modem subsystem 912 can be configured to modulate and / or encode data according to a MCS, for example, an LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. RF unit 914 can be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated / encoded data (e.g., RRC configuration, sidelink resource pool configuration) from modem subsystem 912 (on outbound transmissions) or of transmissions originating from another source such as a UE 115. RF unit 914 can be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 910, modem subsystem 912 and / or RF unit 914 can be separate devices coupled together at BS 105 to enable BS 105 to communicate with other devices.

[0128] RF unit 914 can provide the modulated and / or processed data, e.g. data packets (or more generally data messages that can contain one or more data packets and other information), to antenna 916 for transmission to one or more other devices. This can include, for example, transmission of information to complete attachment to a network and communication with a camped UE 115 according to some aspects of the present disclosure. Antenna 916 can also receive data messages transmitted from other devices and provide the received data messages for processing and / or demodulation at transceiver 910. Transceiver 910 can provide demodulated and decoded data to sidelink configuration module 908 for processing. Antenna 916 can include multiple antennas of similar or different design schemes in order to maintain multiple transmission links.

[0129] In one aspect, BS 900 can include multiple transceivers 910 implementing different RATs (e.g., NR and LTE). In one aspect, BS 900 can include a single transceiver 910 implementing multiple RATs (e.g., NR and LTE). In one aspect, transceiver 910 can include various components, where different combinations of components can implement different RATs.

[0130] Figure 10is a flow diagram of a sidelink system information broadcast procedure 1000 according to some aspects of the present disclosure. Aspects of the procedure 1000 can be performed by a computing device (e.g., a processor, processing circuit, and / or other suitable component) of a wireless communication device or other suitable means for performing the steps. For example, a wireless communication device such as a UE 115, 215, 420, and / or 520 can utilize one or more components, such as the processor 802, the memory 804, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute the steps of the procedure 1000. The procedure 1000 can be at least partially performed in a similar manner as described above with respect to Figures 6-7 The procedure 1000 includes a number of enumerated steps, but aspects of the procedure 1000 can include additional steps before, after, and in between the enumerated steps. In some aspects, one or more of the enumerated steps can be omitted or performed in a different order.

[0131] At block 1010, the first UE can receive, from a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool. The first UE can be a remote UE similar to the remote UEs 420, 520, and 620, and the second UE can be a relay UE similar to the relay UEs 415, 515, and 615. In some instances, the first set of resources is associated with a first link and the second set of resources is associated with a second link different from the first link. In some instances, the first link can be similar to the forward link 602 of Figure 6 and the second link can be similar to the reverse link 604 of Figure 6 In some instances, as shown in Figure 6 , the sidelink resource pool can correspond to the sidelink resource pool 640 and the first set of resources and the second set of resources can correspond to the SL resources labeled with the symbols “F” and “R,” respectively.

[0132] In some aspects, the first UE can receive the TDD configuration in a sidelink broadcast message via a PSBCH. In some aspects, the first UE can receive the TDD configuration in a sidelink discovery message via a PSDCH or a PSBCH during a sidelink discovery procedure.

[0133] In some aspects, the first UE can receive the TDD configuration in SCI via a PSSCH or a PSCCH. In some aspects, the first UE can receive, from the second UE, SCI including a destination identifier identifying the first UE via a PSCCH during a sidelink slot. As part of receiving the TDD configuration, the first UE can receive the TDD configuration from the second UE via at least one of a PSCCH or a PSSCH during the sidelink slot based on the destination identifier (ID). In some aspects, the first UE can receive the TDD configuration in a slot format indicator, for example, according to a periodicity of the slot format indicator.

[0134] In some aspects, the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources, for example, as illustrated by the pattern “FFRRFFRRFF...” of FIG. 6B. In some aspects, the TDD configuration further indicates a periodicity of the TDD resource pattern (e.g., approximately 10, 20, 30, 40, or more slots 631). In some aspects, the TDD resource pattern indicates a first set of slots (e.g., slots 631) and a second set of slots different from the first set of slots, where each resource in the first set of resources is within a slot in the first set of slots and each resource in the second set of resources is within a slot in the second set of slots. In some aspects, the first UE can receive the TDD configuration in a slot format indicator. In some instances, the first UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to receive the TDD configuration. Figure 6

[0135] At block 1020, the first UE can receive, from the second UE, a first communication signal over the first link in a resource of the first set of resources. In some instances, the first UE can receive data on a PSSCH and control signaling on a PSCCH. In some instances, the first UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to receive and process PSSCH sidelink data and PSCCH control signaling.

[0136] ​At block 1030, the first UE can transmit, to the second UE, the first communication signal over the first link in a resource of the first set of resources. In some instances, the first UE can transmit data on a PSSCH and control signaling on a PSCCH. In some instances, the first UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to generate and transmit the PSSCH sidelink data and the PSCCH control signaling.

[0137] Figure 11 FIG. 11 is a flow diagram of a sidelink system information broadcast procedure 1100, in accordance with some aspects of the present disclosure. Aspects of the procedure 1100 can be executed by a computing device (e.g., a processor, processing circuit, and / or other suitable component) of a wireless communication device or other suitable means for performing the steps. For example, a wireless communication device such as a UE 115, 215, 415, and / or 515 can utilize one or more components, such as the processor 802, the memory 804, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute the steps of the procedure 1100. The procedure 1100 can utilize, at least in part, similar mechanisms as the procedure 800 discussed above with respect to FIG. 8. Figures 6-7 As illustrated, the procedure 1100 includes a number of enumerated steps, but aspects of the procedure 1100 can include other steps before, after, and in between the enumerated steps. In some aspects, one or more of the enumerated steps can be omitted or performed in a different order.

[0138] At block 1110, the first UE can transmit, to the second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in the sidelink resource pool. The first UE can be a relay UE similar to the relay UEs 415, 515, and 615, and the second UE can be a remote UE similar to the remote UEs 420, 520, and 620. In some instances, the first set of resources is associated with a first link and the second set of resources is associated with a second link different from the first link. In some instances, the first link can be similar to the forward link 602 of FIG. 6 and the second link can be similar to the reverse link 604 of FIG. 6. Figure 6 In some instances, the first set of resources can be associated with a first set of frequency resources and the second set of resources can be associated with a second set of frequency resources different from the first set of frequency resources. In some instances, the first set of frequency resources can be similar to the frequency resources 606 of FIG. 6 and the second set of frequency resources can be similar to the frequency resources 608 of FIG. 6. Figure 6 In some instances, the first set of resources can be associated with a first set of frequency resources and the second set of resources can be associated with a second set of frequency resources different from the first set of frequency resources. In some instances, the first set of frequency resources can be similar to the frequency resources 606 of FIG. 6 and the second set of frequency resources can be similar to the frequency resources 608 of FIG. 6. Figure 6As shown in the middle, the sidelink resource pool can correspond to the sidelink resource pool 640, and the first and second resource sets can correspond to the SL resources labeled with the symbols “F” and “R,” respectively. In some aspects, the first UE can transmit the TDD configuration in a sidelink broadcast message via a PSBCH. In some aspects, the first UE can transmit the TDD configuration in a sidelink discovery message via a PSDCH or a PSBCH during a sidelink discovery procedure.

[0139] In some aspects, the first UE can transmit the TDD configuration in SCI via a PSSCH or a PSCCH. In some aspects, the first UE can transmit, to the second UE, SCI including a destination identifier identifying the first UE via a PSCCH during a sidelink slot. As part of transmitting the TDD configuration, the first UE can transmit the TDD configuration to the second UE via at least one of a PSCCH or a PSSCH during the sidelink slot based on the destination identifier (ID). In some aspects, the first UE can transmit the TDD configuration in a slot format indicator, for example, according to a periodicity of the slot format indicator.

[0140] In some aspects, the TDD configuration further indicates a TDD resource pattern for the first and second resource sets, for example, as shown by the pattern “FFRRFFRRFF...” of Figure 6 In some aspects, the TDD configuration further indicates a periodicity (e.g., of about 10, 20, 30, 40, or more slots 631) of the TDD resource pattern. In some aspects, the TDD resource pattern indicates a first set of slots (e.g., slots 631) and a second set of slots different from the first set of slots, where each resource in the first resource set is within a slot in the first set of slots and each resource in the second resource set is within a slot in the second set of slots. In some aspects, the first UE can receive the TDD configuration in a slot format indicator. In some instances, the first UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to transmit the TDD configuration.

[0141] At block 1120, the first UE can transmit, to the second UE, a first communication signal over the first link in a resource of the first resource set. In some instances, the first UE can transmit data on a PSSCH and control signaling on a PSCCH. In some instances, the first UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to generate and transmit the PSSCH sidelink data and the PSCCH control signaling.

[0142] At block 1130, the first UE can receive, from the second UE, a first communication signal in a resource of the first set of resources over the first link. In some instances, the first UE can receive data on a PSSCH and control signaling on a PSCCH. In some instances, the second UE can utilize one or more components, such as the processor 802, the sidelink communication module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to receive and process the PSSCH sidelink data and the PSCCH control signaling.

[0143] Information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0144] Example aspects of the present disclosure include:

[0145] Aspect 1. A method of wireless communication performed by a first user equipment (UE), the method comprising: receiving, from a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; receiving, from the second UE, a first communication signal in a resource of the first set of resources over the first link; and transmitting, to the second UE, a second communication signal using a resource of the second set of resources over the second link.

[0146] Aspect 2. The method of aspect 1, wherein receiving the TDD configuration comprises receiving, from the second UE, a sidelink broadcast message including the TDD configuration via a physical sidelink broadcast channel (PSBCH).

[0147] Aspect 3. The method of any of aspects 1-2, wherein receiving the configuration comprises receiving, from the second UE, a sidelink discovery message including the TDD configuration.

[0148] Aspect 4. The method of any of aspects 1-3, wherein receiving the TDD configuration comprises receiving, from the second UE, the TDD configuration via at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).

[0149] Aspect 5. The method of aspect 4, further comprising: receiving, from the second UE, sidelink control information (SCI) including a destination identifier identifying the first UE via the PSCCH during the sidelink slot, wherein receiving the configuration further comprises receiving, from the second UE, the TDD configuration via at least one of the PSCCH or the PSSCH during the sidelink slot based on the destination identifier (ID).

[0150] Aspect 6. The method of any of aspects 1-5, wherein the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources.

[0151] Aspect 7. The method of aspect 6, wherein the TDD configuration further indicates a periodicity of the TDD resource pattern.

[0152] Aspect 8. The method of any of aspects 6-7, wherein the TDD resource pattern indicates a first set of slots and a second set of slots different from the first set of slots, wherein each resource of the first set of resources is within a slot of the first set of slots, and wherein each resource of the second set of resources is within a slot of the second set of slots.

[0153] Aspect 9. The method of any of aspects 6-8, wherein receiving the TDD configuration comprises receiving, from the second UE, a slot format indicator indicating the TDD resource pattern.

[0154] Aspect 10. The method of aspect 9, wherein receiving the slot format indicator is based on a periodicity associated with the slot format indicator.

[0155] Aspect 11. The method of any of aspects 1-10, wherein the first UE is a remote UE, and wherein the second UE is a relay UE.

[0156] Aspect 12. A method of wireless communication performed by a first user equipment (UE), the method comprising: transmitting, to a second UE, a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the first set of resources is associated with a first link, and wherein the second set of resources is associated with a second link different from the first link; transmitting, to the second UE, a first communication signal over the first link using a resource of the first set of resources; and receiving, from the second UE, a second communication signal over the second link in a resource of the second set of resources.

[0157] Aspect 13. The method of aspect 12, wherein transmitting the TDD configuration comprises transmitting, to the second UE via a physical sidelink broadcast channel (PSBCH), a sidelink broadcast message including the TDD configuration.

[0158] Aspect 14. The method of aspect 12, wherein transmitting the configuration comprises transmitting, to the second UE, a sidelink discovery message comprising the TDD configuration.

[0159] Aspect 15. The method of aspect 12, wherein transmitting the TDD configuration comprises transmitting, to the second UE, the TDD configuration via at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).

[0160] Aspect 16. The method of aspect 15, further comprising transmitting, to the second UE, sidelink control information (SCI) comprising a destination identifier identifying the first UE via the PSCCH during the sidelink slot, wherein transmitting the configuration further comprises transmitting, to the second UE, the TDD configuration via at least one of the PSCCH or the PSSCH during the sidelink slot based on the destination identifier (ID).

[0161] Aspect 17. The method of any of aspects 12-16, wherein the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources.

[0162] Aspect 18. The method of aspect 17, wherein the TDD configuration further indicates a periodicity of the TDD resource pattern.

[0163] Aspect 19. The method of aspect 17, wherein the TDD resource pattern indicates a first set of slots and a second set of slots different from the first set of slots, wherein each resource of the first set of resources is within a slot of the first set of slots, and wherein each resource of the second set of resources is within a slot of the second set of slots.

[0164] Aspect 20. The method of any of aspects 17-19, wherein transmitting the TDD configuration comprises transmitting, to the second UE, a slot format indicator indicating the TDD resource pattern.

[0165] Aspect 21. The method of aspect 20, wherein transmitting the slot format indicator is based on a periodicity associated with the slot format indicator.

[0166] Aspect 22. The method of any of aspects 17-21, further comprising determining the TDD resource pattern for the first set of resources and the second set of resources.

[0167] Aspect 23. The method of any of aspects 12-22, further comprising receiving, from a base station (BS), a sidelink resource configuration, wherein transmitting the TDD configuration is based on the received sidelink resource configuration.

[0168] Aspect 24. The method of any of aspects 12-23, wherein the first UE is a relay UE, and wherein the second UE is a remote UE.

[0169] Aspect 25. A first user equipment (UE), comprising a processor and a transceiver configured to perform the actions of any of aspects 1-11.

[0170] Aspect 26. A first user equipment (UE), comprising a processor and a transceiver configured to perform the actions of any of aspects 12-24.

[0171] Aspect 27. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising instructions executable by a first user equipment (UE), wherein the program code comprises code for performing the steps of any of aspects 1-11.

[0172] Aspect 28. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising instructions executable by a first user equipment (UE), wherein the program code comprises code for performing the steps of any of aspects 12-24.

[0173] Aspect 29. A first user equipment (UE) comprising means for performing the steps of any of aspects 1-11.

[0174] Aspect 30. A first user equipment (UE) comprising means for performing the steps of any of aspects 12-24.

[0175] The various illustrative blocks and modules described in connection with the disclosure herein can be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0176] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed as discrete components or other means to accomplish functions. Also, as used herein, including in the claims, "or" as used in a list of items prefaced by "at least one of indicates a disjunctive list such that, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0177] As will be understood by those familiar with the art, numerous modifications, alternatives and equivalents can be made to the materials, devices, structures and methods described herein without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited, except as by the appended claims, which follow and the full scope of equivalents to which such claims are entitled.

Claims

1. A method of wireless communication performed by a first user equipment (UE), the method comprising: receiving, from a second UE, a time division duplex (TDD) configuration that indicates a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the sidelink resource pool is network configured, wherein the first set of resources is associated with a first link and the second set of resources is associated with a second link different from the first link, and wherein the TDD configuration is generated by the second UE according to a resource partitioning updated for the sidelink resource pool according to at least one of traffic demand or traffic conditions on the first link and the second link; receiving, from the second UE, a first communication signal over the first link in a resource of the first set of resources; and transmitting, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

2. The method of claim 1, wherein, the receiving the TDD configuration comprises: receiving, from the second UE, a sidelink broadcast message including the TDD configuration via a physical sidelink broadcast channel (PSBCH).

3. The method of claim 1, wherein, the receiving the TDD configuration comprises: receiving, from the second UE, a sidelink discovery message including the TDD configuration.

4. The method of claim 1, wherein, the receiving the TDD configuration comprises: receiving, from the second UE, the TDD configuration via at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).

5. The method of claim 4, further comprising: receiving, from the second UE, sidelink control information (SCI) including a destination identifier identifying the first UE via the PSCCH during a sidelink slot, wherein the receiving the TDD configuration further comprises: receiving, from the second UE, the TDD configuration via the at least one of the PSCCH or the PSSCH during the sidelink slot based on the destination identifier (ID).

6. The method of claim 1, wherein, the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources.

7. The method of claim 6, wherein, the TDD configuration further indicates a periodicity of the TDD resource pattern.

8. The method of claim 6, wherein, the TDD resource pattern indicates a first set of slots and a second set of slots different from the first set of slots, wherein each resource of the first set of resources is within a slot of the first set of slots, and wherein each resource of the second set of resources is within a slot of the second set of slots.

9. The method of claim 6, wherein, the receiving the TDD configuration comprises: receiving, from the second UE, a slot format indicator indicating the TDD resource pattern.

10. The method of claim 9, wherein, the receiving the slot format indicator is based on a periodicity associated with the slot format indicator.

11. The method of claim 1, wherein, the first UE is a remote UE, and wherein the second UE is a relay UE.

12. A method of wireless communication performed by a first user equipment (UE), the method comprising: updating a resource partition for a sidelink resource pool as a function of at least one of traffic demand or traffic conditions on a first link and a second link different from the first link, wherein the sidelink resource pool is network configured; generating a time division duplex (TDD) configuration indicating a first set of resources time division multiplexed with a second set of resources in the sidelink resource pool as a function of the updated resource partition, wherein the first set of resources is associated with the first link and the second set of resources is associated with the second link; transmitting the TDD configuration to a second UE; transmitting a first communication signal to the second UE over the first link using resources in the first set of resources; and receiving a second communication signal from the second UE over the second link in resources in the second set of resources.

13. The method of claim 12, wherein, the transmitting the TDD configuration comprises: transmitting, to the second UE, a sidelink broadcast message including the TDD configuration via a physical sidelink broadcast channel (PSBCH).

14. The method of claim 12, wherein, the transmitting the TDD configuration comprises: transmitting, to the second UE, a sidelink discovery message including the TDD configuration.

15. The method of claim 12, wherein, the transmitting the TDD configuration comprises: transmitting, to the second UE, the TDD configuration via at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).

16. The method of claim 15, further comprising: transmitting, to the second UE via the PSCCH during a sidelink slot, sidelink control information (SCI) including a destination identifier identifying the first UE, wherein the transmitting the TDD configuration further comprises: transmitting, to the second UE via the at least one of the PSCCH or the PSSCH during the sidelink slot, the TDD configuration based on the destination identifier (ID).

17. The method of claim 12, wherein, the TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources.

18. The method of claim 17, wherein, the TDD configuration further indicates a periodicity of the TDD resource pattern.

19. The method of claim 17, wherein, the TDD resource pattern indicates a first set of slots and a second set of slots different from the first set of slots, wherein each resource in the first set of resources is within a slot in the first set of slots, and wherein each resource in the second set of resources is within a slot in the second set of slots.

20. The method of claim 17, wherein, the transmitting the TDD configuration comprises: transmitting, to the second UE, a slot format indicator indicating the TDD resource pattern.

21. The method of claim 20, wherein, the transmitting the slot format indicator is based on a periodicity associated with the slot format indicator.

22. The method of claim 17, further comprising: determining the TDD resource pattern for the first set of resources and the second set of resources.

23. The method of claim 12, further comprising: receiving, from a base station (BS), a sidelink resource configuration, wherein the transmitting the TDD configuration is based on the received sidelink resource configuration.

24. The method of claim 12, wherein, The first UE is a relay UE, and wherein the second UE is a remote UE.

25. A first user equipment (UE), comprising: one or more memories; and one or more processors coupled with the one or more memories, the one or more processors configured to: receive, from a second UE, a time division duplex (TDD) configuration, the TDD configuration indicating a first set of resources time division multiplexed with a second set of resources in a sidelink resource pool, wherein the sidelink resource pool is network configured, wherein the first set of resources is associated with a first link and the second set of resources is associated with a second link different from the first link, and wherein the TDD configuration is generated by the second UE according to an updated resource partitioning for the sidelink resource pool, the update being according to at least one of traffic demand or traffic conditions on the first link and the second link; receive, from the second UE, a first communication signal over the first link in a resource of the first set of resources; and transmit, to the second UE, a second communication signal over the second link using a resource of the second set of resources.

26. The first UE of claim 25, wherein, The one or more processors configured to receive the TDD configuration are further configured to: receive, from the second UE, a sidelink broadcast message including the TDD configuration via a physical sidelink broadcast channel (PSBCH).

27. The first UE of claim 25, wherein, The one or more processors configured to receive the TDD configuration are further configured to: receive, from the second UE, a sidelink discovery message including the TDD configuration.

28. The first UE of claim 25, wherein, The one or more processors configured to receive the TDD configuration are further configured to: receive, from the second UE, the TDD configuration via at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).

29. The first UE of claim 28, wherein The one or more processors are further configured to receive, from the second UE, sidelink control information (SCI) including a destination identifier identifying the first UE via the PSCCH during a sidelink slot, wherein the one or more processors configured to receive the TDD configuration are further configured to receive, from the second UE, the TDD configuration via the at least one of the PSCCH or the PSSCH during the sidelink slot based on the destination identifier (ID).

30. The first UE of claim 25, wherein, The TDD configuration further indicates a TDD resource pattern for the first set of resources and the second set of resources.

31. The first UE of claim 30, wherein, The TDD configuration further indicates a periodicity of the TDD resource pattern.

32. The first UE of claim 30, wherein, The TDD resource pattern indicates a first set of slots and a second set of slots different from the first set of slots, wherein each resource of the first set of resources is within a slot of the first set of slots, and wherein each resource of the second set of resources is within a slot of the second set of slots.

33. The first UE of claim 30, wherein, The one or more processors configured to receive the TDD configuration are further configured to receive, from the second UE, a slot format indicator indicating the TDD resource pattern.

34. The first UE of claim 33, wherein, The receiving the slot format indicator is based on a periodicity associated with the slot format indicator.

35. The first UE of claim 25, wherein, The first UE is a remote UE, and wherein the second UE is a relay UE.

36. A first user equipment (UE), comprising: one or more memories; and one or more processors coupled with the one or more memories, the one or more processors configured to perform the method of any of claims 12-24.

Images